In January of 2013, a symposium hosted by Delta Science Program and the UC Davis Center for Aquatic Biology and Aquaculture (CABA) titled, What is a Natural Hydrograph in Regulated Rivers? The Science of Natural Flows to the Delta, explored how the hydrologic regime of Delta inflows are impacted by land-use changes, diversions from the watershed, and climate change.
In this installment of coverage, Dr. Bruce Herbold uses conceptual models to show the cascade of responses to altered flow, drawing on four examples from the Sacramento River, and Dr. Sarah Yarnell the discussed ecological cues that native species use in relation to the flow regime and the potential implications for management of Sierra streams and rivers.
DR. BRUCE HERBOLD: Hydrographs and Ecological Functions in the Present-day Landscape of the Sacramento River
Dr. Bruce Herbold, Estuarine Ecology consultant, now retired from USEPA, began by saying he would be focusing on the Sacramento River and its tributaries, and some about the Delta, and he would be focusing on some of the work he has been doing for the EPA. “EPA Headquarters is trying to develop some guidance on how to put flow into discussing water quality concerns for the protection of beneficial uses,” he said. “That all sounds boring, but I don’t find it boring. And I’m going to talk about conceptual models.”
He presented a slide with two pictures, noting it was two different visions of the rivers flowing through the Delta. “The lower right hand corner is an integral part of San Joaquin salmon and steelhead migratory corridor. We talk about flows through there. You know, they don’t do so well no matter what we do as they do up in the upper left corner. So talking about flows independent of geomorphology, especially I think in this system is stupid.”
DR. SARAH YARNELL: Ecological Response to the Unregulated Spring Flow Regime in the Sierra Nevada
Dr. Sarah Yarnell is Associate Project Scientist at the Center for Watershed Sciences, and her presentation was drawn from research she and her colleagues have done regarding the relationships between aquatic native species and instream flow regimes.
Specifically, she will be talking about research they conducted in the northern Sierra mountains draining into the rim dams, some of the research on the restored floodplain on the Cosumnes River, the ecological cues that native species use in relation to the flow regime, the effects of those flow regimes in regulated and unregulated systems, some of the research of climate change impacts on flow regimes, and then talk about some of the potential implications for management in our Sierra and rivers here in California.
Coming up tomorrow: Coverage of the flows conference continues with the presentation by Dr. Clifford Dahm on possible models for flow regimes from around the world, and a panel discussion.
FOR MORE INFORMATION …
- To view the webcast and power point presentations, click here.
- To read all coverage of the Flows Symposium on Maven’s Notebook, click here.
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